1. Field of the Invention
The present invention relates to an electrical connector assembly, and particularly, to an electrical connector assembly with high signal data rates.
2. Description of Related Art
Small form-factor pluggable (SFP) or Mini-GBIC is a compact, hot-pluggable transceiver used for both telecommunication and data communications applications. It interfaces a network device mother board (for a switch, router, media converter or similar device) to a fiber optic or copper networking cable. It is a popular industry format supported by many network component vendors. SFP transceivers are designed to support SONET, Gigabit Ethernet, Fibre Channel, and other communications standards.
SFP transceivers are also available with a copper cable interface, allowing a host device designed primarily for optical fiber communications to also communicate over unshielded twisted pair networking cable or transport SDI video signal over coaxial cable. There are also CWDM and single-fiber “bi-directional” (1310/1490 nm Upstream/Downstream) SFPs. SFP transceivers are commercially available with capability for data rates up to 4.25 Gbit/s. An enhanced standard called SFP+ (defined in SFF-8341 and SFF-8342) supports data rates up to 10.0 Gbit/s. SFP related technologies are also disclosed in U.S. Pat. No. 6,524,134, issued to Flickinger on Feb. 25, 2003, and U.S. Pat. No. 6,517,382, issued to Flickinger on Feb. 11, 2003.
The SFP+ module comprises a host board (printed circuit board) having a row of first mating pads on a top face and a row of second mating pads on a bottom face (referring to page 5 of SFF-8431), the first mating pads and the second mating pads adapted to electrically contact terminals of a receptacle. Multi-layer PCB is commonly known to be made of at least two sub-PCBs stacked together, each sub-PCB having an insulating layer and two conductive layer attached to opposite sides of the insulating layer.
U.S. Pat. No. 7,798,820, issued to Hong on Sep. 21, 2010, discloses an improvement on SFP. One embodiment shows a PCB 50 having one row of contact pads on a bottom surface and two rows of contact pads on a top surface. Another embodiment shows a PCB 60 having two rows of contact pads on a top surface 60B and two rows of contact pads on a bottom surface 60A. It is further contemplated that contact pad configurations can be included on one or both surfaces of the PCB or edge connector. In the design where a PCB has two rows of contact pads on a top surface, it results that the host receptacle then has two rows of contact pins above a receiving slot of the host receptacle. The two rows of contacts pins increase a height of the host receptacle 212 compared to an existing SFP receptacle. At the same time, the two rows of contacts pins are difficult to handle during manufacturing the host receptacle.
Low profile, low cost of manufacturing, higher mating compatibility are trends of the electrical connector and the present invention is towards this purpose.